Correlation between squamous cell carcinoma of the lung and human papillomavirus infection and the relationship to expression of p53 and p16.

The number of non-small-cell lung cancer (NSCLC) patients reported as infected with human papillomavirus (HPV) varies among countries and by race and geographical location. Furthermore, the relationship between HPV and the expressions of p53 and p16 remains unclear. A large cohort of NSCLC patients from Shanghai was studied. Paraffin sections from 128 cases of lung adenocarcinoma (ADC) and 134 cases of squamous cell carcinoma (SQC) were collected from the Shanghai Chest Hospital. Samples were analyzed by polymerase chain reaction (PCR) and reverse dot blot for detection of HPV DNA and by immunohistochemistry for detection of p53 and p16 expressions. The rate of HPV infection in SQC cases was significantly higher than in ADC cases (12.69 versus 3.91%). Females with SQC had a significantly higher rate of HPV infection compared to males with SQC (18.75 versus 7.14%, p = 0.044). HPV infection was correlated with gender and age in SQC but not with the degree of tumor differentiation, TNM stage, or smoking. Koilocytosis was significantly correlated to the tumor differentiation grade, regardless of age and TNM stage. The expressions of p53 and p16 were correlated with HPV infection and the tumor histological type but not with the degree of tumor differentiation, TNM stage, smoking, gender, or age. p53-positive expression was significantly higher in HPV-infected SQC cases than in those not infected with HPV. There was no statistically significant difference in the expression of p16 between the two groups. Data showed that HPV infection may be an important virulence factor in SQC, particularly in female patients. HPV infection appears to be involved in cancer progression in SQC by promoting the expression of p53; however, p16 cannot be used as a surrogate marker for HPV infection in SQC.